Inhibition of cancer cell growth in cisplatin-resistant human oral cancer cells by withaferin-A is mediated via both apoptosis and autophagic cell death
J BUON. 2020 Jan-Feb;25(1):332-337. PMID: 32277651
PURPOSE: Oral cancer is one of the common oral cavity and pharynx cancers and its treatment is limited by early metastasis, late diagnosis and emergence of drug resistance. Herein we investigated the anticancer effects of Withaferin-A against the cisplatin-resistant SCC-4 human oral cancer cells.
METHODS: The proliferation rate of the human oral cancer cells was evaluated by CCK-8 assay. Apoptotic cell death was studied by acridine orange (AO) / ethidium bromide (EB) staining as well as by flow cytometry using annexin V/propidium iodide (PI) staining. Cell cycle analysis was performed by flow cytometry. Reactive oxygen species (ROS) examination was carried out by flow cytometry. Protein expressions were determined by immunoblotting.
RESULTS: The results of the MTT assay showed that Withaferin-A caused decrease in the proliferation of SCC-4 cells and exhibited an IC50 of 14µM. The anticancer effects of Withaferin-A were mainly due to the induction of apoptosis which was linked with upsurge of Bax and depletion of BCl-2. Annexin V/PI assay showed that the apoptotic cells were 0.75, 5.8, 12.4 and 22.66% at 0,7,14 and 28 µM concentrations of Withaferin-A. Withaferin-Aalso caused increase in the ROS and decrease in the MMP levels of the SCC-4 cells. Western blot analysis showed that the expression of LC3B II increased while of p62 decreased remarkably upon treatment with Withaferin-A, suggestive of autophagic cell death. Cell cycle analysis by flow cytometry showed that Withaferin-A caused increase in the G2/M phase cells triggering arrest of cancer cells at the G2/M checkpoint of the cell cycle. Finally, western blot analysis showed that Withaferin-A blocked the MAPK/RAS/RAF signalling pathway in the SCC-4 cells.
CONCLUSIONS: These results suggest that Withaferin-A may prove a potent lead molecule in oral cancer treatment and warrants further investigations.